The receiver in question is an Onkyo TX-DS939. The problem I have is with the left rear channel and the center channel cutting out randomly. The left rear would completely go out but the center would only decrease in volume. If I turn the receiver off and on they would start playing again, but not all the time. I have tried switching speakers and cables around but the problem still exists. I think the problem is internal.

So can anyone give me an idea of what could be wrong? Can this receiver still be repaired?

Thanks for any help.